In the evaluation of patients with pseudohypoacusis, a test that gives at least a suggestion of the patient's true auditory sensitivity is of great value. This report is an evaluation of the application and contribution of auditory brain stem response (ABR) measurement in pseudohypoacusis through a case study approach. Four patients suspected of having pseudohypoacusis on the basis of their histories and initial audiometric results were tested with the ABR procedure. In all cases the auditory sensitivity suggested by ABR was considerably better than the voluntary thresholds obtained on the initial audiograms. Following ABR measurement, all four patients showed marked improvement in voluntary threshold responses, and two gave responses that were within normal limits. Although auditory brain stem response measurement is not a test of hearing, it can be a powerful tool in the identification and quantification of nonorganic hearing loss.